Hi, I feel strange when some chips fails partially. For example the bluetooth wireless headset chip here. It works but sound level has been limited to max 10% and 90% volume covered by hiss noise. Rest of this everything works. The chip gets pretty hot while working. So I figured out that the chip failed partially. How does this happen in electronics devices? It has pretty stable suppy of its own battery. It has minimum external parts.

 

Think of an integrated circuit as a complex printed circuit board. It has different circuits comprising the whole assembly. In a stereo for example, your left channel can fail but the right channel still works. Your FM can fail but the AM still works. The only difference is all the parts in a chip are microscopic. I recently had a microcontroller with 4 analog to digital converters and only one of them failed. The other 3 were fine.

 

Or think of a person in a hospital bed. One second they are alive and the next they are not. Everything required for life is still there, but some piece of the complex system has failed.

 

How does this happen in electronics devices?

Unless the failure has something in common with all devices in a chip (like the power or ground bond wire), it would be unusual for all devices in a package to fail at the same time.

 

There is always electrostatic discharge to consider?

 

There is always electrostatic discharge to consider?

Hi, I am very aware about ESD. 99% repair centre here even do not know what is ESD here. Maybe these types of partial damages happen because of frequent ON and OFF the supply, ESD, Strong shock during handling, heating etc.

 

For most practical purposes any chip "partially" damaged as you describe would require to be replaced, no matter how many of its components are still "intact".

Your concern seems to fit to anyone dedicated to forensic investigation of a damage.

I recall connecting to each other, two Out pins of a PIC 16C57. In due time one went low while the other remained high. Hardly could be programmed after that.

 

For most practical purposes any chip "partially" damaged as you describe would require to be replaced, no matter how many of its components are still "intact".

Your concern seems to fit to anyone dedicated to forensic investigation of a damage.

I recall connecting to each other, two Out pins of a PIC 16C57. In due time one went low while the other remained high. Hardly could be programmed after that.

I always check the errata for logic devices.
Voltages outside the specs can be a sure bet.